em thangs R kalled "arithmatik sequens"
2+4+6+...2006=2*(1+2+3+...1003)
sum av 1+2+3+...=n*(start number+last number)/2
step 1=figger out wot n be...it be 1003
step 2...sum=n*(start number+lastnumber)/2 or (n/2)*(start+last)
=(1003/2)*(1+1003)
but yu start with 2, so yer number=2*(1003/2)*(1004)=1003*1004=1,007,012
The other sequens...1+3+5+...sum=n^2=1003^2
so yu hav 1003*1004 -1003*1003
anser=1003